Pneumatic devices, such as, air brakes and height control valves, such as are used on heavy equipment, have been in use for many years. Pneumatic devices typically utilize a number of pneumatic lines, which must be connected and interconnected to the various devices. The pneumatic device typically comprises a housing to which a number of components may be connected. The housing is provided with a number of openings for receiving various connections and component connections.
Numerous types of connectors may be connected to the housing and may include, for example, threaded connectors, friction connectors and so forth. Push To Connect (PTC) fittings may also be used with various types of housing configurations. PTC fittings present a number of distinct advantages over other types of connectors. For instance, it is a relatively simple matter to connect pneumatic tubing with a PTC fitting as one simply needs to push the connector into a port, where the connector is retained by an interference fit.
Typically, PTC fittings are provided manufactured of a relatively hard plastic. The plastic is typically a highly engineered grade, having high strength characteristics. This means that the plastic material will have relatively little “give” as very high strength characteristics are advantageous for critical applications, such as, vehicle braking and vehicle ride height control.
The pneumatic device housing may also be provided with a highly engineered grade plastic port for receiving the plastic connector. In addition, various portions of the housing may comprise a highly engineered grade plastic with relatively high strength characteristics. Interference fit connectors, such as a PTC fitting, introduce stress to the surrounding material as the introduced stress between the connector and the port, maintains the connection.
However, a problem arises in particular with vehicle air brake and vehicle control valve applications, in part, due to the required relatively high strength characteristics of the PTC fitting. The press fit induces “hoop” stress in the port and subsequently the housing, which often results in fracturing in the surrounding material. Any fracturing of the surrounding material can result in loosening of the connection and/or catastrophic failure of the braking and/or height control system. Any failure of vehicle safety systems is unacceptable.
Therefore, what is desired is a PTC fitting manufactured of a highly engineered grade plastic having high strength characteristics for use in a vehicle air brake and/or height control system that substantially eliminates fracturing in the surrounding material due to introduced stress.
It is still further desired to provide highly reliable vehicle air brake and/or height control system that uses a PTC fitting manufactured of a highly engineered grade plastic having high strength characteristics that is received in a port of the pneumatic device.